The present invention relates to a method of extracting Teichomycin A.sub.2 from a whole culture fermentation broth with a suitable water miscible solvent.
U.S. Pat. No. 4,239,751 discloses the antibiotic Teichomycin A.sub.2 which is obtained by cultivation of strain Actinoplanes teichomyceticus nov. sp. ATTC 31121. Under the nomenclature established in the World Health Organization Handbook for International Non-Proprietary Names (INN), the name "Teichomycin A.sub.2 " has been changed to "Teicoplanin" as the most recent name for this antibiotic factor. Teichomycin A.sub.2 is one of a mixture of antibiotic factors Teichomycin A.sub.1, and Antibiotic 8327 Factor C produced by this strain. U.S. Pat. No. 4,239,751 teaches a method of isolating the antibiotic factors. In the method described in U.S. Pat. No. 4,239,751, the fermentation broth is filtered in order to remove the mycelial cell mass, leaving a mycelial cake. The filtered fermentation broth is then mixed with a water immiscible organic solvent, such as, halogenated C.sub.1 -C.sub.4 hydrocarbons or C.sub.4 -C.sub.6 alkanols, in which the antibiotic mixture is soluble. The water immiscible organic solvent is then separated from the filtered fermentation broth by high-speed centrifugation, concentrated to about 1/10 to 1/20 of its original volume, cooled and allowed to stand until a precipitate (the antibiotic) forms which is recovered by filtration. Additional product may be recovered by extracting the mycelial cake with aqueous acetone. After distillation of the acetone, the aqueous phase is submitted to the same treatment described above for the filtered fermentation broth.